Fluid amplifier

ABSTRACT

The invention relates to a fluid amplifier provided with a jet cavity connected to the atmosphere, exclusively by blow openings. Said cavity containing stream conductors, separating recirculating fluid, necessary for the addition of fluid to be entrained by the jet, from the main stream.

United States Patent [72] lnventors Henk A. M. Verhelst 3240219 3/1966 Dexter et al. 137/81.5 Velp; 3,326227 6/ 1967 Mitchell 137/815 Cornelis J. Van Gorp, Dieren, Netherhntls 3,362,421 1/ 1968 Schaffer 137/81.5

[21] Appl. No. 781,891 3402727 9/1968 Boothe 137/815 [22] Filed Dec. 6, 1968 3420253 1/1969 Griffin 137/815 [45] Patented Mar. 9, 1971 3425,432 2/ 1969 Langley 137/815 [73] Assignee Nederlandse Organisatie voor Toegepast- 3,438384 4/ 1969 Hurvitz 137/81.5 Natuurwetenslnappelijk Onderzoek ten 3,461 777 8/ 1969 Spencer 137/81.5X behoeve van Nijverheid, Handel en Verkeer The Range, Netherlands OTHER REFERENCES [32] Priority Dec. 20,1967 Fluid Oscillator" A. E. Mitchell, I.B.M. Tech. Dsclosure [33] Netherlands Bull. Vol. 5, No. 6, Nov., 1962. p. 25. (Copy in Scien. Lib. &

Prmary Examiner- Samuel Scott 1 LU D AMPL ER Attorney- Watson, Cole, Grindle & Watson 3 Claims, 7 Drawing Figs.

[52] U.S. Cl. 137/815 [51] Int. Cl F15c l/04 [50] Field of Search 137/81.5 ABSTRACT; The invemion re1ates to a fl id lifi vided with a jet cavity connected to the atmos here, exclu- [56] References Cmd sive1y by blow openings. Said cavity containng stream con- UNITED STATES PATENTS ductors, separating recirculating fluid, necessary for the addi- 3107850 10/1963 Warren et al 137/81.5X

tion of fluid to be entrained by the jet, from the main stream.

PATNTEUHAR 91911 3Q568,700

SHEET 1 F 2 FLUID AMPLIFIER The invention relates to an amplifier based on fluid jet effects, in which for the operation of the amplifier necessary addition of fluid, to be entrained by the jet, takes place.

Many types of similar amplifiers are known. Thus there are known amplifiers in which, by placing a wall in close proximity to the jet, the entrainment of fluid by the jet at the side of the wall is checked on purpose. In doing so a deflection of the jet can be obtained as for instance in case of the wall effect amplifiers.

There are, however, also amplifiers known in which a deflection of the jet by walls is avoided on purpose; for these amplifiers, such as for instance the momentum amplifier, an entrainment as free as possible is desirable.

With al! these amplifiers, depending on the type, one or more drawbacks in design occur, which manifest themselves as, for instance, too great an affectivibility by an adjacent amplifier, too great a possibility of interference by dirt and dust from the vicinity or too slow and ragged a response The purpose of the invention is to remove these drawbacks and is characterized in that the addition takes place exclusively by recirculation from a downstream area in an upward direction, the recirculation being separated from the nearest stream area of the main jet by one or more whether or not adjustable stream conductors in the jet cavity, forming one or more paths of recirculation and the jet cavity being exclusively connected with the vicinity by one or more blow openings.

By the means, described in the invention, is achieved that the jet-vicinity is screened from the free vicinity as much as possible and further t is achieved that the entrainment takes place planned.

The wish for a good screening and for a small as possible construction volume have resulted in a tightly embedded jet cavity with stream conductors and with openings that are constructed in such a way that exclusively fluid can be discharged.

Among certain circumstances it may be important that in a path of recirculation there is a damping room, causing the recirculation to run more regularly.

In a particular embodiment of the invention, such as is described hereinafter, the blow openings rise from these damping rooms.

For the proper adjustibility of the recirculation and the fluid to be discharged it may be important to fit one or more whether or not variable constriction(s), in one or more path(s) of recirculation and/or blow opening(s). The invention wil] further be elucidated by means of a drawing with amplifiers according to the prior art and to their improved version according to the invention.

FIG. 1 shows a wall effect amplifer without closing plate according to the prior art.

F IG. 2 shows a wall effect amplifer without closing plate modified according to the invention.

FIG. 3 shows a momentum amplifer without closing plate according to the prior art.

FIG. 4 shows a momentum amplifier without closihg plate modified according to the invention.

FIG. 5 shows a turbulence amplifer according to the prior art.

FIG. 6 shows a turbulence amplifer without closing plate according to the invention.

FIG. 7 shows a cross section according to the VII, VII of the complete amplifier according to FIG. 6.

In the FIGS. like ciphers refer to like elements of the amplifiers.

The wall effect amplifier with OR/NOR function shown in FIG. 1 is provided with a supply 1 for primary fluid, control inputs 2, 2, a suction opening 3 for suctioning from the vicinity secondary fluid to be entrained, a jet cavity 4, two ventilation openings 5 and 6 and two outlets 7 and 8. As a result of suctioning by the main jet 11 via opening 3 the entrainment is asymmetrical, causing jet 11 to deflect preferably to side 9,

which is the case if at the inlets 2 and 2 there is no control signal present.

Jet 11 wil] try to entrain fluid from the vicinity, as long as control at the inlets 2 and 2 is absent and jet 11 attains this by suctioning fluid through opening 3 and through openings 5 and 6, if possible. By choosing a suitable pressure level in the jet cavity 4 it can be arranged that blowing off exclusively takes place through openings 5 and 6, in order to obtain the logical function, however, it is necessary that suctioning is done through opening 3. This causes dust particles to be entrained from the vicinity, which particles may lead to an inter ference of the operation of an amplifer system.

The invention solves the dust problem by embedding the jet cavity as completely as possible and by avoiding suction openings as connections of the jet cavity with the vicinity and by constructing blow openings to the vicinity instead. An amplifier of the type just described is shown in F IG. 2, improved according to indications according to the invention.

Near outlet 15 the side of jet 11 that is turned towards wall 12 can entrain fluid exclusively via recirculation path 13.

Wall 12 of stream conductor 14 takes over the function of wall 10 of FIG. 1. Opening 6 is connected to recirculation path 13. The proportional momentum amplifer shown in FIG. 3 is very sensitive to interferences from the vicinity because of its open construction and moreover has the same drawbacks as regards fouling as the wall effect amplifier described above. Application of the invention to this amplifier results in the embodiment shown in FIG. 4.

In this embodiment these drawbacks are removed.

Jet cavity 4 is embedded; by fitting stream conductors 17, 18 recirculation paths 24, 25 have been constructed, which are connected with the vicinity via outlet openings 19, 20. To avoid wall efiects short circuits 21, 22 have been fixed in stream conductors 17, 18.

The turbulence amplifer shown in F IG. 5 has the drawback of an unplanned recirculation. To reduce interference of the main stream by freely recirculating fluid, resulting in reduced stability and bad switching qualities, the embedding must be carried out loosely. Application of the invention to this turbulence amplifier offers the opportunity to meet the modern demand of miniaturization.

In the plane embodiment of the turbulence amplifer according to the invention shown in F IGS. 6 and 7 jet cavity 4 is provided with stream conductors 17, 18 with short circuits 21, 22 and blow openings 19, 20 connected with recirculation paths 24, 25, which came into existence through these stream conductors 17, 18.

In recirculation paths 24, 25 damping rooms 26, 27 have been fitted that provide a quiet noninterfering recirculation.

In one or more recirculation path(s) and/or blow opening(s) for instance, screw-shaped adjustable constrictions can be fitted, in order to enable the optimalization of the conduct of the amplifer in a certain application.

The amplifier shown in FIGS. 6 and 7 is drawn to a scale of 5:1.

The achievements were by use of air at ambient temperature as fluid and at a supply pressure of 150 mm. head:

Supply stream, Qv l./hr 16. 5

Max. starting pressure, po rnm WK Max. output stream, Q0 l./hr-- 13 Control pressure, ps mmr 25WK Fan out factor, F 6

Switching time, T 1nillisec 1. 5

We claim:

1. A fluid amplifier wherein a main jet is directed into an enclosed jet cavity for selective discharge through either of a pair of angularly related outlets, comprising a stream conductor defining one sidewall of the cavity, said fluid amplifier being formed to define a recirculation path distinct from said outlets extending on the remote side of said stream conductor from the jet cavity, said path being separated from the cavity solely by said stream conductor and communicating with said cavity at upstream and downstream locations, respectively, of

said cavity, for taking a portion of said main jet from said 2. A fluid amplifier as defined claim l, including a blow opening communicating with the recirculation path at said downstream location.

3. Amplifier according to claim 6, wherein in the path of recirculation there is a dampng room. 

1. A fluid amplifier wherein a main jet is directed into an enclosed jet cavity for selective discharge through either of a pair of angularly related outlets, comprising a stream conductor defining one sidewall of the cavity, said fluid amplifier being formed to define a recirculation path distinct from said outlets extending on the remote side of said stream conductor from the jet cavity, said path being separated from the cavity solely by said stream conductor and communicating with said cavity at upstream and downstream locations, respectively, of said cavity, for taking a portion of said main jet from said downstream location and returning it to the main jet at said upstream location, said amplifier further being formed with a control input for directing a control jet into said main jet, transversely thereto at said upstream location, and in a direction opposite to the return of said portion to the main jet for selectively shifting said main jet from one said outlet to the other.
 2. A fluid amplifier as defined claim 1, including a blow opening communicating with the recirculation path at said downstream location.
 3. Amplifier according to claim 6, wherein in the path of recirculation there is a damping room. 